Originally Posted by gypsylady5

It is a small ruler 1/4" wide by 1/4" high. Like a cube, but long. You use it for marking the 1/4" seam. Just another tool that you don't really need, but it is nice at times. I do have one, but I don't use it. I have in the past, I'm just so experienced at the 1/4" that I don't need to mark things any longer except the 1/2 square triangles. I like to mark the sewing lines and this tool could be used for that.